This invention relates to an agricultural mat or ground covering with weed control and moisture control properties. The moisture and weed control properties equal that of an extruded high density polyethylene film with the added benefit of 100% photo and biodegradability.
Present day horticulture for growing field crops varies greatly based on climatic conditions, soil conditions, and types of crops being planted. State-of-the-art techniques being practiced widespread involve the use of a ground mat primarily used for weed control and moisture retention in the soil.
Examples of ground mats used for these purposes can be categorized into two categories. The first and most widely used is a mat produced from extruded high density polyethylene. The mat may or may not contain pigmentation to give the fabric opacity. High opacity is necessary in weed control. The closed high density polyethylene mat acts as an excellent moisture barrier for retaining water in the soil.
The high density polyethylene film is non-degradable and must either be physically removed from the field after harvest or it can be tilled under. Tilling the film under is less satisfactory because it tends not to disperse in the soil but remains for many seasons in long, wide strips which interfere with cultivation in following seasons.
A second type of fabric agricultural matting has been produced from 100% cellulosic fibers. This mat contains black pigment for opacity and is totally retillable after harvest, leaving no residual fabric. The cellulose structure is 100% biodegradable with the exception of the black pigment. This particular mat biodegrades too quickly in areas with extended single growing seasons. The mat is deficient in that it breaks apart before the crops are ripe and allows some weed plants to compete with the crop plants. In addition, the mat does an inefficient job of retaining ground moisture.
U.S. Pat. No. 5,021,285, Ohe et al, proposes a nonwoven sheet for agricultural use made of a hydrophobic non-woven fabric subjected to hydrophilic treatment in which a surfactant is applied to at least part of the surface of the hydrophobic non-woven fabric, the sheet being characterized in that the hydrophilic treatment creates channels that allow water to pass through the obverse surface of the non-woven fabric to the underside thereof and in that the percentage of water retention is within the range of 150-300 wt %. The polymer nature of the fabric prevents same from degrading and as such, such a sheet encounters the same problems as a high density polyethylene polymer matting cover.
U.S. Pat. No. 4,818,585, Ship, Jr., discloses an agricultural protective fabric comprised of two layers of a nondegradable material and a degradable melt blown layer. The fabric is essentially a cover for growing plants and such fabric allows the transmission of air, water and light.
The inventive new agricultural ground cover or mat embodied by the invention combines both the longevity of a film, the moisture holding qualities of a film, along with the degradability of pure cellulose.